Feed control apparatus having a gauging device for a numerically controlled machine tool

ABSTRACT

In a numerically controlled machine tool a feed control apparatus is provided which includes a gauging means for controlling the movement of a movable component, such as a wheel head or a work table, of the machine tool. Control means are coupled to a numerical control means of the numerically controlled machine tool and to the gauging means. The control means will enable a shifting of the numerical control means from a numerical control mode to a jog mode for allowing a miscellaneous function to be performed and from a jog mode to a numerical control mode after a sizing signal is generated by the gauging means whereby the tool is first moved in a coarse numerical mode to a preset position, then the workpiece is gauged while the system is in the jog mode, and finally switched back to a fine numerical control for final machining with a resultant saving in the amount of numerical information required.

ilnited States Patent Takegawa et al.

1 July 24, 1973 Toyoda Koki Kabushiki Kaisha, Kariya-shi, Japan Filed:July 14, 1971 Appl. No.: 162,345

[73] Assignee:

[30] Foreign Application Priority Data July 18, 1970 Japan 45/63079 [56] References Cited UNITED STATES PATENTS 12/1971 Meese ..318/572X2/1956 Gallimore ..318/443 3,605,531 9/1971 lzumi et al. 318/572 XPrimary Examiner-T. E. Lynch Attorney-Norman F. ()blon, Marvin]. Spivzikcl ill [57] ABSTRACT In a numerically controlled machine tool a feedcontrol apparatus is provided which includes a gauging means forcontrolling the movement of a movable component, such as a wheel head ora work table, of the machine tool. Control means are coupled to anumerical control means of the numerically controlled machine tool andto the gauging means. The control means will enable a shifting of thenumerical control means from a numerical control mode to a jog mode forallowing a miscellaneous function to be performed and from a jog mode toa numerical control mode after a sizing signal is generated by thegauging means whereby the tool is first moved in a coarse numerical modeto a preset position, then the workpiece is gauged while the system isin the jog mode, and finally switched back to a fine numerical controlfor final machining with a resultant saving in the amount of numericalinformation required.

8 Claims, 5 Drawing Figures FEED CONTROL APPARATUS HAVING A GAUGINGDEVICE FOR A NUMERICALLY CONTROLLED MACHINE TOOL BACKGROUND OF THEINVENTION 1. Field Of The Invention The present invention relates to afeed control apparatus which enables a tape or numerical control mode ofoperation of a numerical control means to change to a jog mode ofoperation so as to control the feeding movement of a movable componentin accordance with a sizing signal transmitted from a gauging means.

2. Description Of The Prior Art In the conventional numericallycontrolled machine tool, the feeding movement of a movable component,such as a wheel head or a work table, of the machine tool has beencontrolled by a numerical control system in accordance with numericalinformation which has been stored on a permanent record. In the past, ithas thereby been impossible to automatically stop the feeding movementin accordance with a signal from a gauging device before the movablecomponent has been moved in an amount corresponding to the numericalinformation. In a numerically controlled machine tool, and especially ofthe grinding machine type, very precise dimension accuracy is required.Moreover, because of grinding wheel wear and thermal deformation of themachine it has been almost impossible to significantly improve thedimension accuracy if the movable component thereof, such as a grindingwheel head, is controlled only numerically. As a result of the above, anecessity existed for the utilization of a gauging device together withthe numerical control system.

In a prior art numerically controlled grinding machine having a gaugingdevice, a wheel head is slidably mounted on a slide table which in turnis slidably carried on a base. The wheel head is moved by a first feedmeans that is responsive to feed command pulses from a numerical controlsystem, and the slide table is moved by a second feed means whichincludes a hydraulic cylinder. The wheel head is retracted, when theslide table is moved in a backward direction by the second feed means inaccordance with a sizing signal generated by the gauging device. Whilesomewhat satisfactory, in the prior art numerically controlled grindingmachineasdescribed above, two feed means must be provided in order tomove a single wheel head. Such a double slide structure is extremelycomplicated and will, in fact, cause the endurance and accuracy of themachine to reduce. Moreover, since the double slide structure can beutilized for the wheel head, but not for a work table supporting aworkpiece thereon, it has been found to be rather difficult to preciselyposition an end surface of a workpiece relative to the grinding wheel.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide a new and improved unique feed control apparatuswhich enables numerical control means to change from a numerical controlmode to a jog mode in accordance with numerical information and from ajog mode to a numerical control mode in accordance with a sizing signaltransmitted from a gauging means.

Another object of the present invention is the provision of a new andimproved unique feed control apparatus which causes numerical controlmeans to generate feed command pulses for moving a movable component.

A further object of the present invention is the provi sion of a new andimproved unique feed control apparatus which causes numerical controlmeans to generate feed command pulses at a high frequency in accordancewith numerical information and at a low frequency in accordance with afirst sizing signal transmitted from a gauging means and to stop saidfeed command pulses in accordance with a second sizing signal.

Yet a further object of this invention is to provide a new and improvedunique feed control apparatus having a gauging device for a numericallycontrolled machine tool which is of relatively long endurance andinexpensive.

Briefly, in accordance with this invention, these and other objects arein one aspect attained by the provision of a feed control apparatus fora numerically controlled machine tool which includes a gauging devicewhich has a feeler means for making contact with a workpiece and whichwill generate a sizing signal when the feeler means moves to a desiredposition. A control device is coupled to the gauging means and to anumerical control means which controls the machine tool and includes aswitchover means for changing from a tape or numerical control mode to ajog mode for performing a miscellaneous function in accordance withnumerical information and from a jog mode to a tape or numerical'control mode in accordance with the sizing signal transmitted from thegauging device. Feed'means are further provided for causing thenumerical control means to generate feed command pulses for moving amovable component of the machine tool in accordance with the numericalinformation and to stop generating the feed command pulses in accordancewith the sizing signal.

DESCRIPTION OF THE DRAWINGS The foregoing and other objects of thepresent invention will become fully apparent from the following detaileddescription of a preferred embodiment of the present invention withreference to the accompanying Drawings in which:

FIG. 1 is a side view of a numerically controlled grinding machinehaving a gauging device;

' FIG. 2 is a plan view of the machine of FIG. 1 with a block diagramillustrating a numerical control system;

FIG. 3 is an electrical circuit diagram showing a portionof a feedcontrol apparatus;

FIG. 4 is a diagram of an electrical circuit for controlling the circuitof FIG. 3; and,

FIG. 5 is a diagram of an electrical circuit for controlling the motionsof a gauging device.

EMBODIMENT Referring now to the Drawings, wherein like refer encenumerals designate identical or corresponding parts throughouttheseveral views, and more particularly to FIGS. 1 and 2 thereof, wherein anumerically controlled grindingmachine 10 is shown as including a bed 11upon which a wheel head 13 and a work table 16 are slidably mounted. TheWheel head 13 rotatably supports a grinding wheel 12, and the work table16 carries a spindle head 14 and a tail stock 15. The wheel head 13 andthe work table 16 are slidable in directions which are respectivelyperpendicular to'each other. A

feeding screw, not shown, engaged with a nut secured to the wheel head13 is rotatably mounted on the bed 11, and one end of the screw isconnected to a servomotor 18 which is responsive to feed command pulsesby way of a speed reducer 17. Likewise, another feeding screw engagedwith another nut secured to the work table 16 is connected to aservomotor 20 by way of a speed reducer 19. A spindle 21 is rotatablycarried on the spindle head 14 and is driven by a servomotor 22. Aworkpiece W is supported between the centers of the spindle head 14 andthe tail stock 15, and the rotation of the spindle 21 is transmittedthereto by a driving dog.

A first gauging or measuring device 25 is slidably mounted on a support29 which is secured to the bed 11 and can move in forward and backwarddirections. The measuring device 25 includes a pair of feelers 27adapted to come in contact with the periphery of the workpiece W. Thepair of feelers 27 are displaced by a servomotor 28 in response toprogrammed command data so that the point of generation of a sizingsignal can be moved. A detailed description of a measuring devicesuitable for use as the measuring device 25 can be obtained by referenceto US. Pat. No. 3,568,372.

A second gauging or sizing device 30 for positioning the work table 16is mounted on a stand 32 which is secured to the bed 11 and has adownwardly directed feeler 31 for moving into contact with an endsurface of the workpiece W. The sizing device 30 generates a sizingsignal when the feeler 31 is displaced by the end surface of theworkpiece W to a position where the end surface is aligned with a leftside surface of the wheel 12. It should be understood that the positionof the sizing device 30 is compensated for in an amount equal to adressing amount at every side dressing operation on the wheel 12. Inthis manner, the relationship between the side surface of the wheel 12and the point of generation of the sizing signal will be maintained asdescribed above. The sizing device 30 is vertically slidably carried ona slide block 34 that is in turn slidably mounted on a horizontal bar 33secured to a head 35 on the stand 32. A lead screw, not shown, which isrotatably journalled on the head 35 is engaged with the block 34, andone end of the lead screw is connected with an intermittent drive meanshoused within the head 35 such that the position of the sizing device 30will be compensated in accordance with the rotation of the lead screw.The sizing device 30 is also provided with a rack, not shown, which isengaged with a pinion secured to a shaft that is rotatably journalled onthe head 35 and connected to a cylinder by way of a rack and pinionarrangement housed in the head 35 so as to move the sizing device 30 upand down in accordance with the operation of the cylinder.

It should be understood that conventional pulse motors are utilized asthe servomotors 18, 20, 22, 28, and that the pulse motors arerespectively connected to pulse motor drive circuits 41, 42, 43, 44which are in turn responsive to a conventional numerical control device40. In this manner, respective movable components are moved inaccordance with information stored on a tape 49 which is read by a tapereader 48, and which is transmitted to the numerical control device 40.The numerical control device is further connected to a control device 50which is provided for stopping the feeding movements of the wheel head13 and the work table 16 in accordance with the sizing signals. Sincethe electrical circuits for the control device 50 which are utilized forstopping the feeding movement of the wheel head 13 in accordance withthe sizing signal from the measuring device 25 are similar to theelectrical circuits which are utilized for stopping the feeding movementof the work table 16 in accordance with the sizing signal from thesizing device 30, only the electrical circuits for positioning the worktable 16 will be hereinafter described in reference to FIGS. 3 to 5.

Referring now to FIGS. 3 to 5, the various horizontal control conductorsare for convenience designated as L1 to L29 to enable the electricelements connected thereto to be readily located. Moreover, each relayis represented by a mark CR surrounded by a circle and the contact orcontacts of each relay are represented by the same mark as therespective relay together with a contact number. The circuit diagram ofFIG. 3 illustrates the connective relationships of the various selectionswitches and variable resistances for adjusting the frequency of thefeed command pulses, and each of the terminals thereof is connected to aterminal of the numerical control device 40 at a mark 0. Since the tapereader 48 and the numerical control device 40 are conventional and maybe, for example, the numerical control system manufactured by Fujitsu,Ltd., Kawasaki, Japan, and sold as FANUC MODEL 220, they will bedescribed only in brief.

In FIG. 3, a normally closed contact CR1-3 of a relay CR1 is arranged atline L2, a contact SL1 ofa mode selection switch is connected betweenthe contact CR1-3 and a tape or numerical control mode terminal T3 ofthe numerical control device 40, and the other contact SL2 of the modeselection switch is connected between the contact CR1-3 and a jog modeterminal T4 at line L3. While the tape or numerical control modeterminal T3 is connected to a ground terminal T1 by a closing of thecontact SL1, the numerical control device 40 will be in a tape ornumerical control mode where it is conditioned to control the machine 10in accordance with the numerical information transmitted from the tape49. If the contact SL2 is closed by a manual switchover of the modeselection switch, the jog mode terminal T4 will be connected to theground terminal T1 and control device 40 will be shifted from the tapeor numerical control mode to the jog mode where it is conditioned torelease the machine 10 from being numerically controlled. In the tape ornumerical control mode, in order to start the machine 10 under thecontrol of the numerical control device 40, a push type button switchPBl at line L1 or a contact CR5-1 of a relay CR5 must be closed in ashort time for connection of a starting terminal T2 with the groundterminal T1. If the relay CR1 is energized, as a contact CR1-4 of therelay CR1 is connected to the jog mode terminal T4 at line L4, thenormally closed contact CR1-3 will be opened and the contact CR1-4 willbe closed. In accordance therewith, the tape or numerical control modewill be switched off and the jog mode will be automatically switched on.A normally closed contact CR1-5 of the relay CR1, a contact SL3 of aselection switch and a contact CRW+ are serially connected to a wheelhead forwarding terminal T5 at line L5, and a contact CRW- is connectedto a wheel head retracting terminal T6 in parallel with the contactCRW+. A contact SL4 of the selection switch and a contact CRT+ areprovided between the contact CR1-5 and a table right feeding terminal T7at line L6, and a contact CRT- is connected to a table left feedingterminal T8 in parallel with the contact CRT+. [n the jog mode, if theterminal T5 is connected to the ground terminal T1 by a closing of thecontacts SL3 and CRW+, then the wheel head 13 will be advanced and whenthe terminal T6 is grounded by a closing of the contact CRW-, then thewheel head 13 will be retracted. If the contact SL4 is closed because ofswitchover of the selection switch and the contact CRT-lis closed, thenthe table right feeding terminal T7 will be grounded, whereby the worktable 16 will move in a rightward direction. When the table left feedingterminal T8 is grounded by a closing of the contact CRT, then the worktable 16 will move in a leftward direction. A contact CR4-2 of a relayCR4 and a normally closed contact CRIS-3 of a relay CRIS, hereinafterdescribed, are connected between the terminals T7 and T1 at line L7, andif the relay CR4 is energized, the terminal T7 will be grounded and thework table 16 will automatically move rightward in a jog mode. A circuitfor adjusting the frequency of the feed command pulses in a jog mode isillustrated at lines L8 to L12. A variable resistance VRl is connectedbetween pulse frequency changing terminals T9 and T10 of the numericalcontrol device 40 by way of a normally closed contact CRM20-4, and avariable resistance VR2 is provided between the terminals T9 and T10 byway of a contact CRM20-5 and a normally closed contact CR14-l. Avariable resistance VR3 is arranged between the variable resistance VR2and the terminal T10 and is connected in parallel with the contactCRl4-l. The operation of the circuit will be described hereinafter.

In FIG. 4, a relay CRM20 at line L13 is connected to a miscellaneousfunction contact M20 provided in the numerical control device 40. Themiscellaneous function contact M20 is closed by an end surfacepositioning command, which is one of the miscellaneous function commandstransmitted from the tape 49 and is opened in response to energizationof a relay CRMEN, as hereinafter described. The relay CR1 is connectedto a normally closed contact CRIS-4 and a contact CRM20-1 at line L14.The relay CR1 is energized by a closing of the contact CRM20-l and isself-held through its contact CR1-1 for automaticallychanging from atape or numerical control mode to a jog mode. The relay CR4 at line L15is energized by closing of a contact CR1-2 of the relay CR1 and acontact CRLS11-3 that is closed when the sizing device 30 is moved toits lowermost position. Contacts CRIS-1, CR3-3 and a normally closedcontact CR2-2 are provided at line L16 and are connected to the relayCR5. A contact CR13-2 and a relay CR2 are provided in parallel with theserially connected normally closed contact CR2-2, the contact CR3-3 andthe relay CR5 at line L17. A contact CR2-1 at line L18 is arranged inparallel with the contact CRIS-2. Contacts CR4-l, CRIS-2 and a normallyclosed contact CRLS10-3 are arranged at line L19 and are connected to arelay CR3 for switching ofi the jog mode. A contact CR3-1 is provided atline L20 in parallel with the contacts CR4-l and CR15-2 and a contactCRM20-2 is provided at line L20 in parallel with the normally closedcontact CRLS10-3. Contacts CRM20-6, CRLS10-4 and CR13- 4 are connectedat line L21 to the relay CRMEN for signifying completion of themiscellaneous function.

In FIG. 5, a circuit for controlling the motions of the sizing device 30is illustrated. A relay CRLS10 at line L22 is energized by the closingof a limit switch LS10 when the sizing device 30 is moved to itsuppermost position, and a relay CRLSll at line L23 is energized by theclosing of a limit switch LS11 when the sizing device 30 is moved to itslowermost position. Contacts CRM20-3, CRLS10-l and a normally closedcontact CR13-3 are provided at line L24 and are connected to a relayCR12 for enabling a downward movement of the sizing device 30. A contactCR12-1 is provided at line L25 and is arranged in parallel with thecontacts CRM20-3 and CRLS10-l. Contacts CRl2-2, CR5-2, CRLSll-l, anormally closed contact CRLS10-2 and a relay CR13 are connected inseries at line L26 for enabling an upward movement of the sizing device30. A contact CR13-1 is provided at line L27 and is in parallel with thecontacts CR12-2, CR5-2 and CRLSl 1-1. A contact CRM20-4 is also providedat line L27 and is arranged in parallel with the normally closed contactCRLS10-2. A contact CRLSl1-2, a first sizing signal contact S1 of thesizing device 30 and a relay CR14 are connected in series at line L28,and a second sizing signal contact S2 of the sizing device 30 and arelay CR15 are connected to the contact CRLS11-2 at line L29.

The feed control apparatus having a gauging device for a numericallycontrolled machine tool which is constructed as described above willoperate in the following manner. Assuming that the contact SL1 of themode selection switch is in a closed position, then the previousoperation of the machine 10 will have been controlled by the numericalcontrol device 40 in a tape or numerical control mode. Now, the endsurface positioning command will be transmitted from the tape 49 afterthe completion of the previous operation, whereby the contact M20 willbe closed and the relay CRM20 will be energized. The relay CR1 willthereby be energized by the closing of the contact CRM20-l and will beself-held through the contact CR1-1. The normally closed contact CR1-3at line L2 will be opened and the contact CR1-4 at line L4 will beclosed, whereby the tape or numerical control mode will be switched offand the jog mode will be switched on. Since the sizing device 30 will beat its uppermost position, the relay CRLS10 will be energized throughthe limit switch LS10. The relay CR12 will therefore be energized by wayof the contacts CRM20-3 and CRLS10- and the sizing device 30 will movedownward. When the sizing device 30 arrives at its lowermost position,the limit switch LS11 will be closed and the relay CRLSll will beenergized. The relay CR4 at line L15 will therefore be energized by theclosing of the contact CRLS11-3. Since the contact CR4-2 of the relayCR4 at line L7 will be closed, the work table 16 will begin to move in arightward direction. The normally closed contact CRM20-4 at line L8 willbe opened and the contact CRM20-5 will also be closed, whereby thevariable resistance VR2 will be connected between the pulse frequencychanging terminals T9 and T10. in accordance with the above, the highspeed feeding movement of the work table 16 will be carried out by thefeed command pulses at a frequency which corresponds to the resistanceVR2. When the feeler 31 is displaced a given amount by the end surfaceof the workpiece W, the first sizing signal contact Sl will be closed,and the relay CR14 will be energized. Since the normally closed contactCRl4-l at line L12 will be opened, the variable resistances VR2 and VR3will be connected in series between the terminals T9 and T10 so that thework table 16 will be moved at a low speed. Now, when the end surfacebecomes aligned with a left side surface of the wheel 12, the secondsizing signal contact S2 will be closed, and the relay CRIS will beenergized. The normally closed contact CRIS-3 of the relay CRIS at lineL7 will be opened, so that movement of the work table 16 will beimmediately stopped. At the same time the contact CRll-2 at line L19will be closed, so that the relay CR3 will be energized and selfheld bythe contact CR3-1. The contact CR3-4 at line L14 will be opened tothereby deenergize the relay CR1, so that the jog mode will switch overto tape or numerical control mode. The relay CR5 will be energizedthrough the contacts CRIS-1 and CR3-3 so as to close the contact CR5-lat line Ll. Since the contact CR5-2 at line L26 is also closed, therelay CR13 will be energized and self-held through the contact CRl3-1.Subsequently, the relay CR2 will be energized through the contact CRIS-2and self-held through the contact CRZ-l so as to open the normallyclosed contact CR2-2 at line L16. The relay CR5 will be deenergized andthe contact CR5-l at line L1 will be opened. Because of the short timeof closing of the contact CR5-1, the numerical control device 40 willstart its control over the machine in a tape or numerical control mode.However, since a signal for signifying completion of a miscellaneousfunction will not yet be generated, the tape 49 will not be fed for thenext information block. Since the relay CR13 will be energized, thesizing device 30 will move upward, and when it arrives at the uppermostposition, the limit switch LS10 will be operated, and the relay CRMENwill be energized through the contacts CRLS10-4 and CR13-4. Because ofthe energization of the relay CRMEN, the contact M20 will be opened andthe relay CRMZG) will be deenergized. The contact CRM20-6 at line L21will then be opened and the relay CRMEN will thereby be deenergized. Thedeenergization of the relay CRMEN will signify completion of amiscellaneous function and the tape 49 will then be fed for the nextdata block.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. it is thereforeto be understood that within the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and desired to be secured by letters patent ofthe United States is:

1. In a numerically controlled machine tool controlled by numericalcontrol means; a feed control apparatus comprising:

gauging means having a feeler means for making contact with a workpiece,said gauging means generating a sizing signal when at least one machinemovable component is moved to a desired position from a position remotefrom said workpiece, said gauging means further being movable between arest position and a measuring position; and sequence control meanscoupled to said numerical control means and said gauging means, saidcontrol means having a first relay energized in accordance with aclosing of a miscellaneous function contact of said numerical controlmeans, a second relay energized upon energization of said first relayand movement of said gauging means to said measuring position, a thirdrelay energized in accordance with said sizing signal from said gaugingmeans, a fourth relay energized upon energization of said third relay, afirst contact means operably connected to said first means for changingsaid numerical control means from a numerical control mode operation toa jog mode operation in accordance with energization of said firstrelay, a second contact means associated with said second relay forcausing said numerical control means to generate feed command pulses formoving said at least one machine movable component in accordance withenergization of said second relay, third contact means associated withsaid third relay for stopping the movement of said at least one machinemovable component and a fourth contact means operably connected to saidfourth relay for initiating the starting of the numerical control modeoperation by said numerical control means, whereby the numericallycontrolled machine tool is controlled by a reduced amount of numericalcontrol information. 2. In a numerically controlled machine toolcontrolled by numerical control means; a feed control apparatuscomprising:

gauging means having feeler means for making contact with a workpiecemounted on a movable component of said machine tool, said gauging meanshaving a sizing signal contact that is closed when said feeler means ismoved to a desired position, said gauging means further being movablebetween a rest position and a measuring position; and,

sequence control means coupled to said numerical control means and saidgauging means, said control means having a first relay energized inaccordance with a closing of a miscellaneous function contact of saidnumerical control means, a second relay energized upon energization ofsaid first relay and movement of said gauging means to said measuringposition, a third relay connected to said sizing signal contact, afourth relay energized upon energization of said third relay, said firstrelay being deenergized upon energization of said third relay, anormally closed contact of said first relay being connected to anumerical control mode terminal of said numerical control means, acontact of said first relay being connected to a jog mode terminal ofsaid numerical control means, a contact of said second relay and anormally closed contact of said third relay being connected in series toa feeding terminal of said numerical control means, a contact of saidfourth relay being connected to a starting terminal of said numericalcontrol means whereby the numerically controlled machine tool iscontrolled by a reduced amount of numerical control information.

3. A feed control apparatus as set forth in claim 2, wherein saidcontrol means further includes a fifth relay connected to said contactof said third relay in parallel with said fourth relay, a normallyclosed contact of said fifth relay being connected to said fourth relay.

4. A feed control apparatus as set forth in claim 3, wherein saidcontrol means still further includes a sixth relay connected to saidmiscellaneous function contact, a seventh relay connected to a contactof said third relay, a normally closed contact of said seventh relay anda contact of said sixth relay being connected in series to said firstrelay, and a contact of said seventh relay being connected to saidfourth relay.

5. A feed control'apparatus as set forth in claim 4, wherein saidgauging means further includes another sizing signal contact that isclosed when said feeler means is moved to a position that is apredetermined distance away from said desired position, and wherein saidcontrol means further includes an eighth relay connected to said anothersizing signal contact, a first resistance connected between pulsefrequency changing terminals of said numerical control means by way of acontact of said sixth relay and a normally closed contact of said eighthrelay, and a second resistance connected to said first resistance inparallel with said normally closed contact of said eighth relay.

6. In a numerically controlled machine tool controlled by numericalcontrol means; a feed control apparatus comprising;

gauging means having feeler means and generating a sizing signal when atleast one machine movable component is moved' into a desired position;

sequence control means for controlling miscellaneous functions andcomprising first means for changing in accordance with the numericalinformation of said numerical control means from a numerical controlmode operation to a jog mode operation;

second means operably connected to said first means and causing saidnumerical control means to generate feed command pulses for moving saidat least one machine movable component:

third means responsive to said sizing signal from said gauging means forstopping the movement of said atleast one machine movable component;and, fourth means operably connected to said third means and forchanging said numerical control means from said jog operation to, saidnumerical control operation whereby the numerically controlled machinetool is controlled by a reduced amount of numerical control information.

7. In a numerically controlled machine tool controlled by numericalcontrol means; a feed control apparatus comprising:

gauging means having feeler means for making contact with a workpiece,said gauging means generating a sizing signal when at least one machinemovable component is moved to a desired position, said gauging meansfurther being movable between a rest position and a measuring position;and, sequence control means coupled to said numerical control means andsaid gauging means, said control means having a first means energized inaccordance with numerical information of said numerical control meansfor changing said numerical control means from a numerical control modeoperation to a jog mode operation, a second means energized uponenergization of said first means and movement of said gauging means tosaid measuring position for causing said numerical control means togenerate feed command pulses for moving said at least one machinemovable component, a third means energized in accordance with saidsizing signal from said gauging means for stopping the movement of saidat least one machine movable component, and fourth means energized uponenergization of said third means for changing said numerical controlmeans from said jog mode operation to said numerical control operationwhereby the numerically controlled machine tool is controlled by areduced amount of numerical control information. 8. A feed controlapparatus according to claim 7, wherein said first, second, third andfourth means are relay coils and contacts associated therewith.

1. In a numerically controlled machine tool controlled by numericalcontrol means; a feed control apparatus comprising: gauging means havinga feeler means for making contact with a workpiece, said gauging meansgenerating a sizing signal when at least one machine movable componentis moved to a desired position from a position remote from saidworkpiece, said gauging means further being movable between a restposition and a measuring position; and sequence control means coupled tosaid numerical control means and said gauging means, said control meanshaving a first relay energized in accordance with a closing of amiscellaneous function contact of said numerical control means, a secondrelay energized upon energization of said first relay and movement ofsaid gauging means to said measuring position, a third relay energizedin accordance with said sizing signal from said gauging means, a fourthrelay energized upon energization of said third relay, a first contactmeans operably connected to said first means for changing said numericalcontrol means from a numerical control mode operation to a jog modeoperation in accordance with energization of said first relay, a secondcontact means associated with said second relay for causing saidnumerical control means to generate feed command pulses for moving saidat least one machine movable component in accordance with energizationof said second relay, third contact means associated with said thirdrelay for stopping the movement of said at least one machine movablecomponent and a fourth contact means operably connected to said fourthrelay for initiating the starting of the numerical control modeoperation by said numerical control means, whereby the numericallycontrolled machine tool is controlled by a reduced amount of numericalcontrol information.
 2. In a numerically controlled machine toolcontrolled by numerical control means; a feed control apparatuscomprising: gauging means having feeler means for making contact with aworkpiece mounted on a movable component of said machine tool, saidgauging means having a sizing signal contact that is closed when saidfeeler means is moved to a desired position, said gauging means furtherbeing movable between a rest position and a measuring position; and,sequence control means coupled to said numerical control means and saidgauging means, said control means having a first relay energized inaccordance with a closing of a miscellaneous function contact of saidnumerical control means, a second relay energized upon energization ofsaid first relay and movement of said gauging means to said measuringposition, a third relay connected to said sizing signal contact, afourth relay energized upon energization of said third relay, said firstrelay being deenergized upon energization of said third relay, anormally closed contact of said first relay being connected to anumerical control mode terminal of said numerical control means, acontact of said fIrst relay being connected to a jog mode terminal ofsaid numerical control means, a contact of said second relay and anormally closed contact of said third relay being connected in series toa feeding terminal of said numerical control means, a contact of saidfourth relay being connected to a starting terminal of said numericalcontrol means whereby the numerically controlled machine tool iscontrolled by a reduced amount of numerical control information.
 3. Afeed control apparatus as set forth in claim 2, wherein said controlmeans further includes a fifth relay connected to said contact of saidthird relay in parallel with said fourth relay, a normally closedcontact of said fifth relay being connected to said fourth relay.
 4. Afeed control apparatus as set forth in claim 3, wherein said controlmeans still further includes a sixth relay connected to saidmiscellaneous function contact, a seventh relay connected to a contactof said third relay, a normally closed contact of said seventh relay anda contact of said sixth relay being connected in series to said firstrelay, and a contact of said seventh relay being connected to saidfourth relay.
 5. A feed control apparatus as set forth in claim 4,wherein said gauging means further includes another sizing signalcontact that is closed when said feeler means is moved to a positionthat is a predetermined distance away from said desired position, andwherein said control means further includes an eighth relay connected tosaid another sizing signal contact, a first resistance connected betweenpulse frequency changing terminals of said numerical control means byway of a contact of said sixth relay and a normally closed contact ofsaid eighth relay, and a second resistance connected to said firstresistance in parallel with said normally closed contact of said eighthrelay.
 6. In a numerically controlled machine tool controlled bynumerical control means; a feed control apparatus comprising; gaugingmeans having feeler means and generating a sizing signal when at leastone machine movable component is moved into a desired position; sequencecontrol means for controlling miscellaneous functions and comprisingfirst means for changing in accordance with the numerical information ofsaid numerical control means from a numerical control mode operation toa jog mode operation; second means operably connected to said firstmeans and causing said numerical control means to generate feed commandpulses for moving said at least one machine movable component: thirdmeans responsive to said sizing signal from said gauging means forstopping the movement of said at least one machine movable component;and, fourth means operably connected to said third means and forchanging said numerical control means from said jog operation to saidnumerical control operation whereby the numerically controlled machinetool is controlled by a reduced amount of numerical control information.7. In a numerically controlled machine tool controlled by numericalcontrol means; a feed control apparatus comprising: gauging means havingfeeler means for making contact with a workpiece, said gauging meansgenerating a sizing signal when at least one machine movable componentis moved to a desired position, said gauging means further being movablebetween a rest position and a measuring position; and, sequence controlmeans coupled to said numerical control means and said gauging means,said control means having a first means energized in accordance withnumerical information of said numerical control means for changing saidnumerical control means from a numerical control mode operation to a jogmode operation, a second means energized upon energization of said firstmeans and movement of said gauging means to said measuring position forcausing said numerical control means to generate feed command pulses formoving said at least one machine movable component, a third meansenergized in accordance with said sizing Signal from said gauging meansfor stopping the movement of said at least one machine movablecomponent, and fourth means energized upon energization of said thirdmeans for changing said numerical control means from said jog modeoperation to said numerical control operation whereby the numericallycontrolled machine tool is controlled by a reduced amount of numericalcontrol information.
 8. A feed control apparatus according to claim 7,wherein said first, second, third and fourth means are relay coils andcontacts associated therewith.